You know, since I've had my M6 in July, the first thing I put on it was the black silicone case that came with it from JTC...and have NEVER taken it off. Love the feel, and the extra padding it gives it, and it just fits like a perfect glove.
No, it doesn't protect the screen, but I've actually left the OEM secondary plastic covering on front & back from new...and will be finally removing that, and replacing them with this (received a few weeks ago):
http://durasec.com/catalog/multimedi... a43d75f6ce32
Then will have fresh whole front & rear covering, and will put my silicone surrounding back on.